pointer to store the index result in
the repository that contains the given commits
the commit to cherry-pick
the commit to cherry-pick against (eg, HEAD)
the parent of the cherrypick_commit, if it is a merge
the merge options (or null for defaults)
zero on success, -1 on failure.
Cherry-picks the given commit against the given "our" commit, producing an index that reflects the result of the cherry-pick.
The returned index must be freed explicitly with git_index_free.